Process and device for separating off a volatile component

A process for separating off at least one volatile component from off-gases in cement clinker production, which comprises the steps of:

• passing raw materials for the cement clinker production through a preheater with heat exchange with the off-gases and the raw materials being then burnt in a rotary kiln, wherein, owing to a heating of the raw materials in the preheater, the volatile component bound in the raw materials is vaporized and separated off from the off-gases, the passing step containing the further following steps of:
• feeding a first raw material stream having a higher concentration of the volatile component into a first line of the preheater, wherein the first line of the preheater being operated with a first substream of the off-gases of the rotary kiln;
• feeding a second raw material stream having a lower concentration of the volatile component than in the first raw material stream into a second line of the preheater, the second line of the preheater being operated with a second substream of the off-gases of the rotary kiln;
• separating off the volatile component from the first substream of the off-gases passed through the first line of the preheater and a separated volatile component is not reintroduced to the preheater;
• and
• combining the first raw material stream heated to a temperature of at least 250° C. by heat exchange with the first substream of the off-gases in the first line of the preheater, at a generally constant temperature of at least 250° C., with the second raw material stream of the second line of the preheater.